scholarly journals Feel the light – sight independent negative phototactic response in octopus' arms

2021 ◽  
pp. jeb.237529
Author(s):  
Itamar Katz ◽  
Tal Shomrat ◽  
Nir Nesher
Keyword(s):  
Light Beam ◽  
Behavioral Experiments ◽  
Research Results ◽  
Local Activation ◽  
Diverse Species ◽  
Phototactic Response ◽  
Surgical Manipulations ◽  
And Control ◽  
The Brain

Controlling the octopus's flexible hyper-redundant body is a challenging task. It is assumed that the octopus has poor proprioception which has driven the development of unique mechanisms for efficient body control. Here we report on such a mechanism, a phototactic response of extraocular photoreception. Extraocular photoreception has been observed in many and diverse species. Previous research on cephalopods revealed that increased illumination on their skin evokes chromatophore expansion. Recently, the mechanism was investigated and has been termed 'light-activated chromatophore expansion' (LACE). In this work we show that in response to illumination, the arm tip reacts in a reflex-like manner, folding in and moving away from the light beam. We applied a set of behavioral experiments and surgical manipulations to elucidate and characterize this phototactic response. We found that in contrast to the local activation and control of LACE, the phototactic response is mediated by the brain, although it is expressed in a reflex-like pattern. Our research results and observations led us to propose that the phototaxis is a means for protecting the arms in an instinctive manner from potential daytime predators such as fish and crabs, that could identify the worm-like tips as food. Indeed, observation of behaving octopuses revealed that the arm tips are folded-in during the daytime, while at night they are extended. Thus, the phototactic response might compensate for the octopus's poor proprioception by keeping the arms folded in illuminated areas, without the need to be aware of their state.

SPECIFIC PROPERTIES OF TUBULIN IN THE PREFRONTAL CORTEX IN CONTROL, SCHIZOPHRENIA AND VASCULAR DEMENTIA

2020 ◽  
pp. 65-71
Author(s):  
Burbaeva G.Sh. ◽  
Androsova L.V. ◽  
Vorobyeva E.A. ◽  
Savushkina O.K.
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Prefrontal Cortex ◽  
Vascular Dementia ◽  
Binding Activity ◽  
Nephelometric Method ◽  
Rate Of Polymerization ◽  
Mental Diseases ◽  
And Control ◽  
The Brain

The aim of the study was to evaluate the rate of polymerization of tubulin into microtubules and determine the level of colchicine binding (colchicine-binding activity of tubulin) in the prefrontal cortex in schizophrenia, vascular dementia (VD) and control. Colchicine-binding activity of tubulin was determined by Sherlinе in tubulin-enriched extracts of proteins from the samples. Measurement of light scattering during the polymerization of the tubulin was carried out using the nephelometric method at a wavelength of 450-550 nm. There was a significant decrease in colchicine-binding activity and the rate of tubulin polymerization in the prefrontal cortex in both diseases, and in VD to a greater extent than in schizophrenia. The obtained results suggest that not only in Alzheimer's disease, but also in other mental diseases such as schizophrenia and VD, there is a decrease in the level of tubulin in the prefrontal cortex of the brain, although to a lesser extent than in Alzheimer's disease, and consequently the amount of microtubules.

scholarly journals Neuron–Glia Interactions in Tuberous Sclerosis Complex Affect the Synaptic Balance in 2D and Organoid Cultures

Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 134
Author(s):  
Stephanie Dooves ◽  
Arianne J. H. van Velthoven ◽  
Linda G. Suciati ◽  
Vivi M. Heine
Keyword(s):  
Tuberous Sclerosis ◽  
Glial Cells ◽  
Tuberous Sclerosis Complex ◽  
Neuronal Development ◽  
Transmembrane Proteins ◽  
Significant Burden ◽  
Epidermal Growth ◽  
And Control ◽  
Egf Signaling ◽  
The Brain

Tuberous sclerosis complex (TSC) is a genetic disease affecting the brain. Neurological symptoms like epilepsy and neurodevelopmental issues cause a significant burden on patients. Both neurons and glial cells are affected by TSC mutations. Previous studies have shown changes in the excitation/inhibition balance (E/I balance) in TSC. Astrocytes are known to be important for neuronal development, and astrocytic dysfunction can cause changes in the E/I balance. We hypothesized that astrocytes affect the synaptic balance in TSC. TSC patient-derived stem cells were differentiated into astrocytes, which showed increased proliferation compared to control astrocytes. RNA sequencing revealed changes in gene expression, which were related to epidermal growth factor (EGF) signaling and enriched for genes that coded for secreted or transmembrane proteins. Control neurons were cultured in astrocyte-conditioned medium (ACM) of TSC and control astrocytes. After culture in TSC ACM, neurons showed an altered synaptic balance, with an increase in the percentage of VGAT+ synapses. These findings were confirmed in organoids, presenting a spontaneous 3D organization of neurons and glial cells. To conclude, this study shows that TSC astrocytes are affected and secrete factors that alter the synaptic balance. As an altered E/I balance may underlie many of the neurological TSC symptoms, astrocytes may provide new therapeutic targets.

Intact Priming for Novel Perceptual Representations in Amnesia

1997 ◽  
Vol 9 (6) ◽  
pp. 699-713 ◽  
Author(s):  
Stephan B. Hamann ◽  
Larry R. Squire
Keyword(s):  
Recognition Memory ◽  
Declarative Memory ◽  
Brain Structures ◽  
Perceptual Identification ◽  
Single Exposure ◽  
Memory Representations ◽  
Perceptual Representations ◽  
The Creation ◽  
And Control ◽  
The Brain

Recent studies have challenged the notion that priming for ostensibly novel stimuli such as pseudowords (REAB) reflects the creation of new representations. Priming for such stimuli could instead reflect the activation of familiar memory representations that are orthographically similar (READ) and/or the activation of subparts of stimuli (RE, EX, AR), which are familar because they occur commonly in English. We addressed this issue in three experiments that assessed perceptual identification priming and recognition memory for novel and familiar letter strings in amnesic patients and control subjects. Priming for words, pseudowords, and orthographically illegal nonwords was fully intact in the amnesic patients following a single exposure, whereas recognition memory was impaired for the same items. Thus, priming can occur for stimuli that are unlikely to have preexisting representations. Words and pseudowords exhibited twice as much priming as illegal nonwords, suggesting that activation may contribute to priming for words and wordlike stimuli. Additional results showed that priming for illegal nonwords resulted from the formation of new perceptual associations among the component letters of each nonword rather than the activation of individual letter representations. In summary, the results demonstrate that priming following a single exposure can depend on the creation of new perceptual representations and that such priming is independent of the brain structures essential for declarative memory.

Quantitative Brain Measurements in Chronic Schizophrenia

1972 ◽  
Vol 121 (562) ◽  
pp. 259-264 ◽  
Author(s):  
Randall Rosenthal ◽  
Llewellyn B. Bigelow
Keyword(s):  
Chronic Schizophrenia ◽  
Controlled Study ◽  
Normal Variation ◽  
Autopsy Material ◽  
Organic Brain Disease ◽  
Schizophrenic Patients ◽  
Organic Brain ◽  
Brain Measurements ◽  
And Control ◽  
The Brain

Despite extensive gross and microscopic scrutiny, no consistent pathological findings have emerged from studies of autopsy material from schizophrenic patients. Dunlap (1924) carried out the first controlled study involving schizophrenic and control brains and concluded that ‘there was not even a suspicion of consistent organic brain disease as a basis for the psychosis of schizophrenia’. More recently both Wolf and Cowen (1952), and Weinstein (1954), reviewed the neuropathological literature and concluded that there were no consistent findings at autopsy that could be construed as characteristic of schizophrenia. These authors felt that earlier claims were based on failure to appreciate the range of normal variation in the brain as well as a failure to include an adequate control population in the study.

Perbaikan Kualitas Produk Batu Bata Merah Dengan Metode Six Sigma-Dmaic (Studi Kasus Cv. Ghatan Fatahillah Karawang)

UNISTEK ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 6-10
Author(s):  
Egar Naufal Ari Satya ◽  
Wahyudin Wahyudin
Keyword(s):  
Quality Control ◽  
Customer Satisfaction ◽  
Six Sigma ◽  
Quality Standards ◽  
Research Results ◽  
Machine Performance ◽  
Fishbone Diagram ◽  
And Control ◽  
Dmaic Method

Abstrak. Dunia industri yang semakin berkembang akan mengakibatkan banyaknya persaingan. Perus-ahaan yang dapat bersaing adalah perusahaan yang dapat menjaga  kualitas produknya dengan baik sehingga dapat memenuhi kepuasan konsumen. Maka dari itu diperlukan pengendalian kualitas. Penelitian ini difokuskan pada penurunan cacat pada produk batu bata merah di CV. Ghatan Fatahillah dengan metode Six Sigma-DMAIC (Define, Measure, Analyze, Improve, dan Control). Dari hasil penelitian didapatkan DPMO sebesar 36.212 dengan nilai sigma 3,29. Jenis cacat yang paling sering terjadi pada batu bata merah yaitu pecah/patah yaitu sebesar 4.327 atau 59,81% dari total keseluruhan produk yang cacat.  Hasil dari tahap analyze dengan fishbone diagram, ditetapkan penyebab dari pecah/cacat, yaitu: pekerja kurang paham standar kualitas, tidak adanya pemeriksaan produk, pekerja kurang paham prosedur kerja, kinerja mesin tidak stabil, pekerja kurang teliti,  jumlah penggilingan tidak menentu, dan komposisi batu bata tidak menentu. Maka perlu dilakukan usulan perbaikan agar dapat mengurangi jumlah produk yang cacat pada batu bata merah. Kata kunci: DMAIC, DPMO, Pengendalian Kualitas, Six Sigma Abstract. The growing industrial world will result in a lot of competition. Companies that can compete are companies that can maintain the quality of their products well so that they can meet customer satisfaction. Therefore, quality control is needed. This research is focused on reducing defects in red brick products at CV. Ghatan Fatahillah with the Six Sigma-DMAIC method (Define, Measure, Analyze, Improve, and Control). From the research results obtained DPMO of 36,212 with a sigma value of 3.29. The type of defect that most often occurs in red bricks is broken / broken, which is 4,327 or 59.81% of the total defective products. The results of the Analyze stage with the fishbone diagram showed that the causes of breakage / defects were determined, namely: workers do not understand quality standards, lack of product inspection, workers do not understand work procedures, unstable machine performance, workers are not careful, the number of mills is erratic, and composition erratic bricks. So it is necessary to make improvement proposals in order to reduce the number of defective products in red bricks. Keywords: DMAIC, DPMO, Quality Control, Six Sigma

Intranasal administration of mitochondria improves spatial memory in olfactory bulbectomized mice

2021 ◽  
pp. 153537022110568
Author(s):  
Natalia V Bobkova ◽  
Daria Y Zhdanova ◽  
Natalia V Belosludtseva ◽  
Nikita V Penkov ◽  
Galina D Mironova
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Spatial Memory ◽  
Intranasal Administration ◽  
Brain Structures ◽  
Brain Regions ◽  
Dependent Manner ◽  
Behavioral Experiments ◽  
Hippocampal Cell Culture ◽  
The Brain

Here, we found that functionally active mitochondria isolated from the brain of NMRI donor mice and administrated intranasally to recipient mice penetrated the brain structures in a dose-dependent manner. The injected mitochondria labeled with the MitoTracker Red localized in different brain regions, including the neocortex and hippocampus, which are responsible for memory and affected by degeneration in patients with Alzheimer's disease. In behavioral experiments, intranasal microinjections of brain mitochondria of native NMRI mice improved spatial memory in the olfactory bulbectomized (OBX) mice with Alzheimer’s type degeneration. Control OBX mice demonstrated loss of spatial memory tested in the Morris water maze. Immunocytochemical analysis revealed that allogeneic mitochondria colocalized with the markers of astrocytes and neurons in hippocampal cell culture. The results suggest that a non-invasive route intranasal administration of mitochondria may be a promising approach to the treatment of neurodegenerative diseases characterized, like Alzheimer's disease, by mitochondrial dysfunction.

Interleukin-1β and neurogenic control of blood pressure in normal rats and rats with chronic renal failure

2000 ◽  
Vol 279 (6) ◽  
pp. H2786-H2796 ◽  
Author(s):  
Shaohua Ye ◽  
Pantea Mozayeni ◽  
Michael Gamburd ◽  
Huiqin Zhong ◽  
Vito M. Campese
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Renal Failure ◽  
Nervous System ◽  
Chronic Renal Failure ◽  
Lateral Ventricle ◽  
Mrna Abundance ◽  
And Control ◽  
The Brain ◽  
Local Expression

Increased sympathetic nervous system (SNS) activity plays a role in the genesis of hypertension in rats with chronic renal failure (CRF). The rise in central SNS activity is mitigated by increased local expression of neuronal nitric oxide synthase (NOS) mRNA and NO2/NO3 production. Because interleukin (IL)-1β may activate nitric oxide in the brain, we have tested the hypothesis that IL-1β may modulate the activity of the SNS via regulation of the local expression of neuronal NOS (nNOS) in the brain of CRF and control rats. To this end, we first found that administration of IL-1β in the lateral ventricle of control and CRF rats decreased blood pressure and norepinephrine (NE) secretion from the posterior hypothalamus (PH) and increased NOS mRNA expression. Second, we observed that an acute or chronic injection of an IL-1β-specific antibody in the lateral ventricle raised blood pressure and NE secretion from the PH and decreased NOS mRNA abundance in the PH of control and CRF rats. Finally, we measured the IL-1β mRNA abundance in the PH, locus coeruleus, and paraventricular nuclei of CRF and control rats by RT-PCR and found it to be greater in CRF rats than in control rats. In conclusion, these studies have shown that IL-1β modulates the activity of the SNS in the central nervous system and that this modulation is mediated by increased local expression of nNOS mRNA.

scholarly journals Effect of an extract of Aloe vera on the biodistribution of sodium pertechnetate (Na99mTcO4) in rats

2009 ◽  
Vol 24 (5) ◽  
pp. 383-386 ◽  
Author(s):  
Cecília Maria de Carvalho Xavier Holanda ◽  
Monique Batista da Costa ◽  
Natália Chilinque Zambão da Silva ◽  
Maurício Ferreira da Silva Júnior ◽  
Vanessa Santos de Arruda Barbosa ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Aloe Vera ◽  
Treated Group ◽  
Control Group ◽  
Blood Levels ◽  
Control Groups ◽  
High Increase ◽  
Tropical Plant ◽  
And Control ◽  
The Brain

PURPOSE: Aloe vera is a tropical plant popularly known in Brazil as babosa. We have investigated the effect of aqueous extract of Aloe vera on the biodistribution of Na99mTcO4 and laboratorial parameters in Wistar rats. METHODS: Twelve animals were divided into treated and control groups. In the treated group, Aloe vera was given by gavage (5mg/mL/day) during 10 days. The control group received sorbitol by the same way and period. One hour after the last dose, we injected 0.1mL of Na99mTcO4 by orbital plexus. After 60 min, all the animals were killed. Samples were harvested from the brain, liver, heart, muscle, pancreas, stomach, femur, kidneys, blood, testis and thyroid and the percentage of radioactivity (%ATI/g) was determined. Biochemical dosages were performed. RESULTS: There was a significant increase of %ATI/g in blood, femur, kidneys, liver, stomach, testis and thyroid and also in blood levels of AST and ALT. A significant decrease in levels of glucose, cholesterol, triglycerides, creatinine and urea occurred. The statistical analyses were performed by Mann-Whitney test and T-Student test (p<0.05). CONCLUSION: The aqueous extract of Aloe vera facilitated the uptake of Na99mTcO4 in organs of rats and it was responsible to a high increase of levels of AST and ALT.

scholarly journals Molecular Mechanism of Systemic Delivery of Neural Precursor Cells to the Brain: Assembly of Brain Endothelial Apical Cups and Control of Transmigration by CD44

Stem Cells ◽  
2008 ◽  
Vol 26 (7) ◽  
pp. 1673-1682 ◽  
Author(s):  
Christine Rampon ◽  
Nicolas Weiss ◽  
Cyrille Deboux ◽  
Nathalie Chaverot ◽  
Florence Miller ◽  
...  
Keyword(s):  
Molecular Mechanism ◽  
Precursor Cells ◽  
Neural Precursor Cells ◽  
Neural Precursor ◽  
Systemic Delivery ◽  
And Control ◽  
The Brain

scholarly journals Population rate-coding predicts correctly that human sound localization depends on sound intensity

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Antje Ihlefeld ◽  
Nima Alamatsaz ◽  
Robert M Shapley
Keyword(s):  
Sound Localization ◽  
Sound Intensity ◽  
Spatial Location ◽  
Spike Rate ◽  
Behavioral Experiments ◽  
Interaural Time Differences ◽  
Sound Levels ◽  
Rate Coding ◽  
The Brain ◽  
Population Rate

Human sound localization is an important computation performed by the brain. Models of sound localization commonly assume that sound lateralization from interaural time differences is level invariant. Here we observe that two prevalent theories of sound localization make opposing predictions. The labelled-line model encodes location through tuned representations of spatial location and predicts that perceived direction is level invariant. In contrast, the hemispheric-difference model encodes location through spike-rate and predicts that perceived direction becomes medially biased at low sound levels. Here, behavioral experiments find that softer sounds are perceived closer to midline than louder sounds, favoring rate-coding models of human sound localization. Analogously, visual depth perception, which is based on interocular disparity, depends on the contrast of the target. The similar results in hearing and vision suggest that the brain may use a canonical computation of location: encoding perceived location through population spike rate relative to baseline.

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